P-Blocks Elements - Chapter No 12
Right Answers have been shown below in red color.
1. Boron has ______ ionization potential value.
a) High
b) Low
c) Complex
d) Simple
2. The formula for borax is __________.
a) Na2CO3
b) Na2B4O7.10H2O
c) B2O3
d) H3BO3
3. Borax is used in making__________.
a) Water
b) Hydrogen gas
c) Manufacture of optical & hard glass
d) None of these
4. The formula for orthoboric acid is __________.
a) H2BO3
b) H3BO3
c) H2SO4
d) NaOH
5. The chemical equation, when orthoboric acid reacts with “Na2CO3” is __________.
a) Na2B4O7 + CO → 2NaBO2 + CO(BO2)2
b) 4H3BO3 + Na2CO3 → Na24O7 + CO2 + 6H2O
c) H3BO3 + 3C2H5OH → B(OC2H5)3+3H2O
d) None of these
5. The chemical equation, when orthoboric acid reacts with “Na2CO3” is __________.
a) Na2B4O7 + CO → 2NaBO2 + CO(BO2)2
b) 4H3BO3 + Na2CO3 → Na2B4O7 + CO2 + 6H2O
c) H3BO3 + 3C2H5OH → B(OC2H5)3 + 3H2O
d) None of these
6. The heat energy for reaction 4Al + 3O2 → 2Al2O3 is __________.
a) 𐤃H = -798.18 K cal/m
b) 𐤃H = 9310 K Cal/m
c) 𐤃H = + 798.18 K cal/m
d) None of these
7. When aluminum reacts with dil.HCl then _______ gas is produced
a) Hydrogen
b) Nitrogen
c) Oxygen
d) None of these
8. When aluminum reacts with chlorine then __________ is formed
a) SO2
b) AlCl3
c) Al (OH)3
d) CH4
9. “Al” is a __________ metal.
a) Dissolving
b) Lighter
c) Slow
d) None of these
10. Alums are used for the __________ of hard water.
a) Sizing
b) Purification
c) Cotton
d) None of these
11. The carbon has __________ allotropic forms.
a) Two
b) Three
c) Four
d) Five
12. Diamond is the __________ substance.
a) Inert
b) Coke
c) Hardest
d) Soft
13. The melting point of carbon is very__________.
a) High
b) Low
c) Graphite
d) Increases
14. At 20ºC, the diamond has __________ density.
a) 441.9 gm/cm3
b) 3.51 gm/cm2
c) 571. gm/cm3
d) 751 gm/cm3
15. Diamond has __________ refractive index.
a) Slow
b) Less
c) High
d) Hea
16. Diamond is used for the __________ of glass.
a) Cutting
b) Electricity
c) Room temperature
d) Drilling
17. Graphite has __________density at 20ºC.
a) 471.5 gm/cm3
b) 2.2 gm/cm3
c) 9.41 gm/cm3
d) None of these
17. Graphite has __________density at 20ºC.
a) 471.5 gm/cm3
b) 2.2 gm/cm3
c) 9.41 gm/cm3
d) None of these
18. When “C” burns with “O2” at 700ºC then _________ gas is obtained
a) CO2
b) CO
c) CaCO3
d) CF4
19. The formula for lead monoxide is _________.
a) PbO
b) PbS
c) PbCl3
d) None of these
20. PbO + H2 → __________.
a) PbH2 +O2
b) Pb + H2O
c) Pb + CO
d) Pb + CO2
